1. Field of the Invention
The present invention relates to the field of a light emitting diode (LED), and more particularly to an LED light emitting device manufacturing method and an LED light emitting device capable of adjusting color temperature easily.
2. Description of the Related Art
Cone cells of human eyes may be divided into three different photoreceptors according to light-absorbing pigments receiving the primary colors (red, green and blue) of a visible spectrum respectively, and colors are defined and described by these cone cells. To standardize the colors sensed by human eyes, COMMISSION INTERNATIONALE DE L'ECLAIRAGE, CIE) established in 1931 has created CIE1931 color spaces to simplify the simulation value XYX of the three primary colors and obtain a CIE1931 xy chromaticity diagram, which are common standard coordinates. In other words, if the CIE1931 xy chromaticity coordinates of a certain color are obtained, then color characters can be defined specifically in chromaticity. For example, the independent standards of white light must be defined in the field of illumination, and Planck's blackbody radiation is one of them. When the spectrum of a certain light source is the same as the spectrum of the blackbody radiation, the absolute temperature parameter of the surface of the blackbody may be used to define the color and spectrum of the light, so as to express light color by color temperature, know the color temperature and the chromaticity coordinates of the light source, and confirm the color characteristics of the light source.
Light emitting diode (LED) is a very popular light source for illumination lamps and generally emits a light with a narrow spectral range, so that a single LED can just emits a light with a fixed color tone, and the color mixing principle is used to select an LED light source for a lamp with the required color temperature. When an illumination lamp requires a specific color temperature, the lamp adopts white light LEDs with a single color temperature or different color temperatures to form a cold or warm color illumination light source. In design and manufacture, the lamp is intuitively designed with a white light source or each LED light source disposed on the lamp base is designed with a white light source in order to avoid the light mixing action that follows and non-uniform color temperature of the light produced the mixed light, and the light color of the white light LED is adjusted by mixing the primary colors (RGB) of the LED chip (RGB) or by mixing and supplementing the color light of the phosphor and the LED chip. With reference to FIG. 1, at least one blue light LED chip 20, a red phosphor 21 and a green phosphor 22a are used to package and form a white light LED 2, and the white light LED 2 adjusts the condition of the red phosphor 21 and the green phosphor 22 to form a specific light source according to the required color temperature, wherein the red phosphor 21 and the green phosphor 22 as shown in FIG. 1 are provided for illustrating the present invention wherein they are packaged into the white light LED 2 but not in the form of phosphor. And then, at least one the white light LED 2 is installed to a circuit board 3 to form a conventional light emitting device 4 according to the required elements such as brightness. The conventional light emitting device 4 may be applied as a main light source for lamps such as bulbs. With reference to FIGS. 2A-2D for different configurations of the conventional light emitting device 4 respectively, we can observe that the method of adjusting the concentration of the phosphors is very inconvenient, because the color temperature of a light varies with a change of concentration of any phosphor. When the proportion and concentration of the phosphors are changed, and the result after the change cannot be simulated in advance, so that it is necessary to measure the related data every time after the white light LED 2 is packaged, and thus increasing the level of difficult of product development and design significantly.
In view of the aforementioned problems of the prior art, the inventor of the present invention based on years of experience in the related industry to conduct extensive researches and experiments and finally designed a manufacturing method of a LED light emitting device capable of adjusting the color temperature easily and developed an LED light emitting device in accordance with the present invention to overcome the problems of the prior art.